Expansion-drill



(No Model.) I

O. A. SELBY.

BXPANSION DRILL. 0 No. 440,065. Patented Nov. 4, 1890.

1 4 Wznesses: i Invanor:

UNITED STATES PATENT OFFICE.

CHARLES ALBERT SELEY, OF SUMNER, IOWA.

EXPANSlQN-DRILL.

SPCFCATION forming part of etters Patent No. 440,065, dated November 4, 1890.

Application file March 21, 1890r Serial No. 344,820. (No model.)

To aZZ Vwhom it may concem:

Be it known that I, CHARLES ALBERT SE- LEY, 'of Sumner, in the county of Bremer and State of Iowa, have invented certain new and useful Improvements in EXpansion-Drills; and I do hereby declare the following to be a full, clear, and exact description of the invention, such as will enable others skilled in the art to which it pertains to make and use it, reference being had to the accompanying drawing, which forms part of this specification.

My invention relates to an improvement in eXpansion-drills; and it consists in the combination and particular construction hereinafter described, and pointed out in the claim.

The objects of my invention are to provide an eXpansion-drill in which the bit Will automatically adjust itself without the use of a spring or other appliance, and to so construct the upper end of the bit and the opening in which it is placed that no dirt or gravel can get into the opening and interfere with the operation `of the bit.

The accompanying drawing represents a side elevation of an expansion-drill which embodies my invention, partly in section.

A represents a drill of any suitable construction, but which is especially adapted for boring Wells. At any suitable distance above its lower Cutting-edge there is made a Vertical transverse slot or opening' B through the drill, and in this opening is pivoted the automatically-adjustable bit O. The head O' eX- tends entirely through the opening B, and the bit proper is secured to one edge thereof outside ot' the outer side of the drill proper. By thus Shaping the head and securing the bit to it, as just described, the bit will rest in a Vertical position against the drill proper without cutting the drill away, and thus forming cavities for the collection of gravel and dirt. The raisin g of the bit, as shown in dotted lines, does not expo'se the opening B any more than when it is in a Vertical position, as is the case in expansion-drills heretofore constructed. The opening through the drill is just enough longer than the headrofl the bit to prevent gravel or dirt from getting in the opening and thus interfering with the action ofthe bit. Vhen the bit is opened outward, the opposite corners of its head strike against the top and bottom of the slot in which it is pivoted, and thus transfer all of the strain from the pivot to the body of the bit itself. The lower inner end of the bit is beveled outward, as shown, and the cutting-edge of the body extends in the same direction as the cutting-edge of the drill itself.

In operation the lower end of the bit automatically moves outward to its full extent, and reanis or cuts a larger opening than is made by the' drill itself. No spring is necessary to force this bit outward, and there being no cavity for a spring or other attachment, and the head of the bit being made to snugly fit in a hole in the drill, no dirt orother substances can get into the slot so as to interfere with the action of the bit. The lower Cutting-edge of the bit stands at a right angle to the slot in which the head is pivoted, so as to give to the bit a greater cutting capacity, and to make it Stronger and more durable than it Would be if the head of the bit Were attached to the drill in the usual manner.

Having thus described my invention, I claim- The combination, With a drill having a longitudinal transverse opening' made through it, of a straight bit having its lower cutting end inclined outwardly, whereby it is automatically forced outward by the turning of the 'drill, a longitudinal head which fits in the said transverse opening, the bit proper being secured to the head outside of the outer surface of the drill, Whereby it normally extends parallel with the drill` and a pivotal pin which passes through the head and bit, substantially as shown and described.

In testimony whereof I afiix my signature in presence of two witnesses.

CHARLES ALBERT sELEY.

XVitnessea:

J osIAH CARPENTER, ABY CARPENTER. 

